diff --git a/README.md b/README.md
index 2c2d3b5..4c44783 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ An [Arduino](http://arduino.cc/) library for sending and receiving data using [L
 | DIO0 | 2 |
 
 
-`NSS`, `NRESET`, and `DIO0` pins can be changed by using `LoRa.setPins(ss, reset, dio0)`. `DIO0` pin is optional, it is only needed for receive callback mode.
+`NSS`, `NRESET`, and `DIO0` pins can be changed by using `LoRa.setPins(ss, reset, dio0)`. `DIO0` pin is optional, it is only needed for receive callback mode. If `DIO0` pin is used, it **must** be interrupt capable via [`attachInterrupt(...)`](https://www.arduino.cc/en/Reference/AttachInterrupt).
 
 ## Installation